Karima Kahlaoui

Processing the emotions in words: The complementary contributions of the left and right hemispheres

A dual-process model is suggested for the processing of words with emotional meaning in the cerebral hemispheres. While the right hemisphere and valence hypotheses have long been used to explain the results of research on emotional stimulus processing, including nonverbal and verbal stimuli, data on emotional word processing are mostly inconsistent with both hypotheses. Three complementary lines of research data from behavioral, electrophysiological, and neuroimaging studies seem to suggest that both hemispheres have access to the meanings of emotional words, although their time course of activation may be different. The left hemisphere activates these words automatically early in processing, whereas the right hemisphere gains access to emotional words slowly when attention is recruited by the meaning of these words in a controlled manner. This processing dichotomy probably corroborates the complementary roles the two hemispheres play in data processing.

The Right Hemisphere's Contribution to the Processing of Semantic Relationships between Words

For more than a century, language has been assumed to be entirely dependent on left-hemisphere-based processing. However, since the early 1960s, evidence for the right hemispheres involvement in language processing, in particular in the semantic processing of words, has emerged. At least three complementary approaches have provided evidence of this: behavioral data from neurologically intact participants, the study of brain-damaged patients and the use of neuroimaging methods. The goal of this article is to review the major evidence from these three sources concerning the nature of the right hemispheres contribution to the semantic processing of words. Overall, the data from these studies suggest that both the right hemisphere and the left hemisphere are crucial for semantic processing, with both hemispheres being involved in different ways in the processing of semantic knowledge.

Functional near-infrared spectroscopy: looking at the brain and language mystery from a different angle.

The last decades have brought great advances in our ways to investigate how brain is engaged in language and communication. Numerous techniques are now available to explore the mystery of how language is organized within the brain in function. These techniques take advantage of various brain activity processes, such as electrical activity (e.g., Evoked Related Potentials; ERPs), metabolism (e.g., Positron Emission Tomography; PET) or hemodynamic phenomena (e.g., functional Magnetic Resonance Imaging fMRI). Each of these approaches offers the possibility to look at language processing within different time windows of the communicating brain in action, over a range of complementary spatial and time resolutions. This special issue of Brain and Language is focussed on a specific functional neuroimaging technique introduced many decades ago: functional Near-Infra-Red Spectroscopy (fNIRS). NIRS was introduced more than 30 years ago and this technique has been slowly but constantly evolving from basic clinical research to clinical applications (Wolf, Ferrari, & Quaresima, 2007). Although fNIRS is not a new technique, it has not yet become a popular choice in the brain and language research domain. This is unfortunate, since fNIRS can study the communicating brain from a complementary angle. Specifically, as discussed by some of the pioneers in the field (see the article by Quaresima, Bisconti, & Ferrari, 2012), fNIRS can capture not only regional changes in deoxyhemoglobin, similarly to the Blood Oxygenation Level Dependant (BOLD) signal in fMRI, but it is also the only non-invasive technique able to measure changes in oxyhemoglobin. Indeed, the oxyhemoglobin being diamagnetic, it has no effect on the BOLD signal. It is true that for the time being, fNIRS can only allow for the exploration of cortical regions, and that this exploration is limited to a few centimetres from the scalp, in comparison to fMRI able to explore the full brain. However, fNIRS allows the participant to be seated in front of a screen or engaged in communication without any interference from the environmental noise, and with some degree of tolerance for movements. These aspects constitute a significant advantage of fNIRS over the restrained, non-natural environments of other functional neuroimaging techniques (e.g., fMRI, PET). Moreover, as in the case of ERPs, fNIRS is a low-cost option, which does not require a dedicated environment, and has the potential to follow biotracers in the future. fNIRS has thus a tremendous translational potential, in particular regarding the study of complex clinical populations for whom fMRI is not adapted, such as very young or very old participants. This special issue brings together a series of fNIRS studies that illustrate the analysis of different components of language process-

Pictures and words priming and category effects in object processing

1 Which importance for P 450 Cytochromes in drug interactions? A study from the French PharmacoVigilance Database AC Danton, A Sommet, G Durrieu, H Bagheri and JL Montastruc Service de Pharmacologie, Faculté de Médecine, Toulouse, France Objective: Cytochromes (CYPs) are a superfamily of isoenzymes involved in drug metabolism. The main isoenzymes are CYP 1A2, 2C9, 2D6 and 3A4. However, their relative importance in clinically significant interactions remains unknown. The aim of the present study was to investigate in the French PharmacoVigilance Database (FPVD) the number and characteristics of drug-drug interactions possibly explained by involvement of CYPs. Methods: Spontaneous notifications of Adverse Drug Reactions (ADRs) recorded by Toulouse Midi-Pyrénées PharmacoVigilance Centre between 1st January and 31st August 2008 were extracted from the FPVD. For each observation, we recorded the main characteristics of patients (age, gender), involved drug(s) (name, pharmacological class and involved CYP) and induced ADRs (type, ‘seriousness’, evolution). Results: Between 1st January and 31st August 2008, 1205 ADRs were registered by Toulouse Midi-Pyrénées PharmacoVigilance Centre into the FPVD. They involved 683 women (56.6%). In 12 cases, patients were less than 1 year old and in 14 cases, age was not informed. For other observations, mean age was 55.8 (median value: 58.0) years. Among these ADRs, 410 (34%) were ‘serious’ (including 24 fatal outcomes), 356 involved only one drug and 730 did not involve any drug interaction. Finally, 119 reports (i.e. 9.9% of registered ADRs) involved one (or more) drug interaction related to CYPs. Among these 119 notifications, the most frequently involved CYP was 3A4/5 (n = 81), followed by 2C19 (n = 20), 2C9 (n = 16), 2D6 (n = 16) and 2E1 (n = 1). In 13 notifications, several CYPs were involved. Drugs more frequently involved in this kind of drug interaction were amiodarone (n = 21) followed by proton pump inhibitors (n = 11), meprobamate (n = 9), antiretrovirals (n = 9) and rifampicine (n = 6). There was no major difference in ‘seriousness’ or evolution of ADRs between CYP-related interactions and others. In 22 cases, ADRs were possibly due to CYP-related drug interaction (18.5% of CYP-related drug interactions). Conclusion: CYP-related drug interactions are found in around 10% of ADRs registered in the FPVD. The most frequently involved CYPs are 3A4/5 (68%) followed by 2C19 (17%). This CYP-involving interaction leads to clinically significant consequences (ADR) in almost one case out of five. These data underline the importance of CYPs not only in drug interactions but also in mechanisms of ADRs.

Semantic judgment words by Farsi-speaking left- and right-hemisphere damaged individuals

their performance on both concrete and abstract words was significantly worse than NC (processing of both word types were problematic; p < 0.02 for RTs and p < 0.05 for error rates). The results regarding the respective performance for concrete and abstract word in Farsi are not similar to those obtained in other languages. This apparently surprising result will be discussed by reference to the characteristics of concrete and abstracts words in Farsi. Taken as they are, these results would suggest that the integrity of the right hemisphere is more important for the processing of concrete words in Farsi, and that the integrity of the left hemisphere is necessary for unaffected processing of both concrete and abstract words.

Hemispheric specialization for the semantic processing of words during aging: A near-infrared spectroscopy study

Hemispheric specialization for the semantic processing of words during aging: A near-infrared spectroscopy study Karima Kahlaoui , Virginie Vlasblom , Frederic Lesage , Nourredine Senhadji , Habib Benali , Yves Joanette a,b Centre de Recherche Institut universitaire de geriatrie de Montreal, 4545 Queen-Mary, Montreal, Que., Canada H3W 1W5 Faculte de Medecine, 2900, boulevard Edouard-Montpetit, Montreal, Que., Canada H3T 1J4 E-mail address: karima.kahlaoui@umontreal.ca (K. Kahlaoui)